ABS ECU

mcgregor · Unread post by **mcgregor** » 09 Dec 2008, 08:16

Hi
Can anyone tell me where the ABS ECU is located in a 2001 Xantia HDI 110 please. I have an ABS alarm light up and I suspect it is one wheel sensor and need to check out the resistance but I have no idea where the ECU is located. Any help gratefully accepted.
Cheers
Dave

addo · Unread post by **addo** » 09 Dec 2008, 11:08

Dave, are you able to get any more specific information from the diagnostic socket under the dash? I've never had an ABS fault, so I don't know how specific the logging is.

From memory, my ABS controller has a multipin plug on it, so the ECU may be self-contained.

Regards, Adam.

mcgregor · Unread post by **mcgregor** » 09 Dec 2008, 11:11

Adam
That is exactly what I am looking for (the ABS ECU multiplug) Where is it? Is it under the bonnet or under the dash?

KP · Unread post by KP » 09 Dec 2008, 11:35

It on the passenger side of the engine bay usually just in front of the LHM resevior.

Should have a good few pipes into it and then the multiplug on side or top depending on varient.

mcgregor · Unread post by **mcgregor** » 09 Dec 2008, 11:37

Brilliant. Thanks very much.
Dave

mcgregor · Unread post by **mcgregor** » 10 Dec 2008, 07:50

I found a photo of the ABS unit plug in a previous thread so I tested the plug last night and got results of 3 out of the 4 showing 1070 ohms while the LHR (is that N/S?) showed 1028 ohms. Is a 42 ohm loss enough to be giving the problems with the ABS unit? Sometimes it resets and the light goes out when I first move off but then it returns after a minute or two.
As before any info gratefully recieved before I go out and spend £60+ on a new rear sensor.
Cheers
Dave

Unread post by **CitroJim** » 10 Dec 2008, 08:03

mcgregor wrote:Is a 42 ohm loss enough to be giving the problems with the ABS unit?

In my experience Dave, yes

The ABS ECU is very sensitive to even small changes in sensor resistance. 42 ohms is enough.

If you could get your car on a Lexia, you'll find the iffy sensor is reported as being out of specification and every now and again it will light the ABS warning lamp.

Shame it's a rear sensor as they're not as easy as front ones but on the bright side, at least they're a little cheaper

It'll be worth just checking the sensor connector for dirt and good contact before ordering a new one though.

Sorry to be the bearer of bad news Dave

mcgregor · Unread post by **mcgregor** » 10 Dec 2008, 08:12

Thanks Jim you really just said what I was thinking. Still not sure about LHR though. Any thoughts?

Unread post by **CitroJim** » 10 Dec 2008, 08:17

LHR is indeed the N/S Dave. L and R is from the viewpoint of sitting in the drivers seat.

mcgregor · Unread post by **mcgregor** » 10 Dec 2008, 09:03

I thought it was but needed confirmation. Thanks very much Jim.
Cheers
Dave

KP · Unread post by KP » 10 Dec 2008, 10:07

I have a full rear swing arm if you wanted to make the job a bit easier comes with hub as well?

Depends where you are though as they are very heavy....

mcgregor · Unread post by **mcgregor** » 11 Dec 2008, 07:48

Thanks for that but I live in far NE Scotland, but I reckon a sensor change will not tax my abilities too much.
Cheers
Dave